Vehicle configuration with motors that rotate between a lifting position and a thrusting position

ABSTRACT

This disclosure describes a configuration of an unmanned aerial vehicle (“UAV”) that will facilitate extended flight duration. The UAV may have any number of lifting motors. For example, the UAV may include four lifting motors (also known as a quad-copter), eight lifting motors (also known as an octo-copter), etc. Likewise, to improve the efficiency of horizontal flight, the UAV also includes a pivot assembly that may rotate about an axis from a lifting position to a thrusting position. The pivot assembly may include two or more offset motors that generate a differential force that will cause the pivot assembly to rotate between the lifting position and the thrusting position without the need for any additional motors or gears.

CLAIM OF PRIORITY

This application is a divisional of and claims the benefit of U.S.application Ser. No. 14/626,357, filed Feb. 19, 2015, entitled “VehicleConfiguration with Motors that Rotate Between a Lifting Position and aThrusting Position,” which is incorporated by reference herein in itsentirety.

BACKGROUND

Multi-propeller aerial vehicles (e.g., quad-copters, octo-copters) arebecoming more common. All such vehicles require a body configurationthat will support the separation of the multiple propellers, the controlcomponents, the power supply (e.g., battery), etc. However, there is abalance between weight and duration of flight. As the weight increases,for example to support more components, the flight duration willdecrease.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description is set forth with reference to the accompanyingfigures. In the figures, the left-most digit(s) of a reference numberidentifies the figure in which the reference number first appears. Theuse of the same reference numbers in different figures indicates similaror identical items or features.

FIG. 1 depicts a block diagram of a top-down view of an unmanned aerialvehicle with a pivot assembly in a lifting position, according to animplementation.

FIG. 2 depicts a block diagram of a top-down view of an unmanned aerialvehicle with a pivot assembly in a thrusting position, according to animplementation.

FIG. 3 depicts a block diagram of another top-down view of an unmannedaerial vehicle with a pivot assembly in a lifting position, according toan implementation.

FIG. 4 depicts a block diagram of another top-down view of an unmannedaerial vehicle with a pivot assembly in a thrusting position, accordingto an implementation.

FIG. 5 depicts a block diagram of another top-down view of an unmannedaerial vehicle with a pivot assembly in a lifting position, according toan implementation.

FIG. 6 depicts a block diagram of a side-view of a portion of a pivotassembly in a lifting position, according to an implementation.

FIG. 7 depicts a block diagram of a side-view of a portion of a pivotassembly in a thrusting position, according to an implementation.

FIG. 8 is a block diagram of an illustrative implementation of anunmanned aerial vehicle control system, according to an implementation.

While implementations are described herein by way of example, thoseskilled in the art will recognize that the implementations are notlimited to the examples or drawings described. It should be understoodthat the drawings and detailed description thereto are not intended tolimit implementations to the particular form disclosed but, on thecontrary, the intention is to cover all modifications, equivalents andalternatives falling within the spirit and scope as defined by theappended claims. The headings used herein are for organizationalpurposes only and are not meant to be used to limit the scope of thedescription or the claims. As used throughout this application, the word“may” is used in a permissive sense (i.e., meaning having the potentialto), rather than the mandatory sense (i.e., meaning must). Similarly,the words “include,” “including,” and “includes” mean including, but notlimited to. Additionally, as used herein, the term “coupled” may referto two or more components connected together, whether that connection ispermanent (e.g., welded) or temporary (e.g., bolted), direct or indirect(i.e., through an intermediary), mechanical, chemical, optical, orelectrical. Furthermore, as used herein, “horizontal” flight refers toflight traveling in a direction substantially parallel to the ground(i.e., sea level), and that “vertical” flight refers to flight travelingsubstantially radially outward from the earth's center. It should beunderstood by those having ordinary skill that trajectories may includecomponents of both “horizontal” and “vertical” flight vectors.

DETAILED DESCRIPTION

This disclosure describes a configuration of an unmanned aerial vehicle(“UAV”) that will facilitate extended flight duration. The UAV may haveany number of lifting motors. For example, the UAV may include fourlifting motors (also known as a quad-copter), eight lifting motors (alsoknown as an octo-copter), etc. Likewise, to improve the efficiency ofhorizontal flight, the UAV also includes a pivot assembly that mayrotate about an axis from a lifting position to a thrusting position.The pivot assembly may include two or more motors, referred to herein asthrusting motors, that are offset from one another about the axis. Whenthe pivot assembly is in a lifting position, the thrusting motors andcorresponding propellers, referred to herein as thrusting propellers,are aligned with the frame of the UAV 100 and may be used to providelifting force to aid in the vertical lift of the UAV. When the pivotassembly is in a thrusting position, the thrusting motors andcorresponding thrusting propellers are positioned approximatelyperpendicular to the frame of the UAV 100 and may be engaged to providehorizontal thrust to move the UAV in a substantially horizontaldirection.

In some implementations, when the pivot assembly is in the thrustingposition and the thrusting motors and corresponding thrusting propellersare generating thrust, the rotational speed of the lifting motors may bereduced, thereby improving efficiency and reducing power consumption ofthe UAV. Likewise, in some implementations, the UAV may include a wingto aid in the vertical lift of the UAV while the UAV is moving in asubstantially horizontal direction.

The thrusting motors and corresponding thrusting propellers of the pivotassembly are offset with respect to one another about an axis so thatthe two thrusting motors may be used to rotate the pivot assemblybetween the lifting position and the thrusting position. For example,rather than utilizing another motor, such as a servo motor, a gearassembly, or other additional component to rotate the pivot assemblybetween the lifting position and the thrusting position, the forcegenerated by a first thrusting motor and corresponding thrustingpropeller may be increased or decreased with respect to the forcegenerated by a second, offset thrusting motor and correspondingthrusting propeller to move the pivot assembly between the liftingposition and the thrusting position. For example, if the force generatedby the first motor is greater than the force generated by the secondmotor, the resulting differential force will cause the pivot assembly torotate from the lifting position to the thrusting position. If the forcegenerated by the second motor is greater than the force generated by thefirst motor, the resulting differential force will cause the pivotassembly to rotate from the thrusting position to the lifting position.In another implementation, rather than offsetting two motors, a singlemotor and propeller, in which the motor is capable of rotating thepropeller in either direction, may be utilized. For example, if themotor rotates the propeller in a first rotational direction (e.g.,clockwise), the force generated by the propeller may cause the pivotassembly to rotate so that the motor and propeller are in a thrustingposition. If the motor rotates the propeller in a second rotationaldirection (e.g., counter-clockwise), the force generated may cause thepivot assembly to rotate so that the motor and propeller are in alifting position.

To further improve the efficiency of the UAV, in some implementations,the frame, motor arms, wing, propellers, and/or other components of theUAV may be formed of one or more lightweight materials, such as carbonfiber, graphite, machined aluminum, titanium, fiberglass, etc.

Regardless of material, each of the motor arms, and/or motor housing maybe hollow, thereby reducing weight and providing a cavity through whichone or more wires and/or cables may be passed and/or in which othercomponents may be housed. For example, wires that connect the motors(e.g., lifting motors, thrusting motors) to components located in oraround the frame (e.g., electronic speed control (“ESC”)) may be passedthrough the inner portion of one or more of the motor housings and motorarms.

While the examples discussed herein describe the implementations withrespect to a UAV, the implementations may likewise be utilized on othertypes of vehicles. For example, the pivot assembly described herein maybe utilized on an aerial vehicle, a ground based vehicle, an unmannedground based vehicle, a water based vehicle, and/or an unmanned waterbased vehicle.

FIG. 1 illustrates a block diagram of a top-down view of a UAV 100 witha pivot assembly 107 in a lifting position, according to animplementation. As illustrated, the UAV 100 includes a frame 104. Theframe 104 or body of the UAV 100 may be formed of any suitable material,such as graphite, carbon fiber, aluminum, etc., or any combinationthereof. In this example, the frame 104 of the UAV 100 is formed ofmachined aluminum in a rectangular shape.

Mounted to the frame are two motor arms 105-1, 105-2. In this example,the motor arms 105-1, 105-2 are approximately the same length, arearranged substantially parallel to one another and perpendicular to theframe 104. In other implementations, the motor arms 105 may be ofdifferent lengths (e.g., the front motor arm 105-1 may be shorter thanthe rear motor arm 105-2 and/or arranged at different locations on theUAV 100.

Mounted to each end of the motor arms 105 are lifting motors 106-1,106-2, 106-3, and 106-4. The lifting motor may be mounted so thatpropeller shaft of the lifting motor that mounts to the propeller 102 isfacing downward with respect to the UAV 100. In other implementations,the lifting motors may be mounted with the propeller shaft facingupwards with respect to the UAV 100. In still other implementations, oneor more of the lifting motors may be mounted with the propeller shaftfacing downward and one or more of the lifting motors may be mountedwith the propeller shaft facing upward. In other implementations, thelifting motors may be mounted at other angles with respect to the frameof the UAV 100. The lifting motors may be any form of motor capable ofgenerating enough rotational speed with the propellers to lift the UAV100 and any engaged payload, thereby enabling aerial transport of thepayload.

In some implementations, the lifting motors 106 may be encased within amotor housing that has an aerodynamic shape to improve the airflowaround the motors while the UAV 100 is moving in a direction thatincludes a horizontal component. The motor housings may be formed of anymaterial, such as carbon fiber, aluminum, graphite, etc.

Mounted to each lifting motor is a lifting propeller 102-1, 102-2,102-3, and 102-4. The lifting propellers 102 may be any form ofpropeller (e.g., graphite, carbon fiber) and of a size sufficient tolift the UAV 100 and any payload engaged by the UAV 100. For example,the lifting propellers 102 may each be carbon fiber propellers having adimension or diameter of twenty-nine inches. While the illustration ofFIG. 1 shows the lifting propellers 102 all of a same size, in someimplementations, one or more of the lifting propellers 102 may bedifferent sizes and/or dimensions. Likewise, while this example includesfour lifting propellers, in other implementations, more or fewerpropellers may be utilized as lifting propellers. Likewise, in someimplementations, the propellers may be positioned at different locationson the UAV 100. In addition, alternative methods of propulsion may beutilized as “motors” in implementations described herein. For example,fans, jets, turbojets, turbo fans, jet engines, internal combustionengines, and the like may be used (either with propellers or otherdevices) to provide lift for the UAV.

Mounted to a first end, or front end, of the frame 104 of the UAV 100 isone or more antennas 108. The antennas 108 may be used to transmitand/or receive wireless communications. For example, the antennas 108may be utilized for Wi-Fi, satellite, near field communication (“NFC”),cellular communication, or any other form of wireless communication.Other components, such as cameras, time of flight sensors, distancedetermining elements, gimbals, etc. may likewise be mounted to the frontof the frame 104 of the UAV 100.

A UAV control system 114 is also mounted to the frame 104. In thisexample, the UAV control system 114 is mounted to a top of the frame104. In other implementations, the UAV control system 114, or componentsthereof, may be mounted or positioned at other locations of the UAV 100.The UAV control system 114, as discussed in further detail below withrespect to FIG. 8, controls the operation, routing, navigation,communication, motor controls, and the payload engagement mechanism ofthe UAV 100.

Likewise, the UAV 100 includes one or more power modules (not shown).The power modules may be mounted to various locations on the frame 104of the UAV 100. For example, in some implementations, four power modulesmay be mounted to an underneath side of the frame 104 within a fuselage(not shown). The power modules for the UAV 100 may be in the form ofbattery power, solar power, gas power, super capacitor, fuel cell,alternative power generation source, or a combination thereof. Forexample, the power modules may each be a 6000 mAh lithium-ion polymerbattery, or polymer lithium ion (Li-poly, Li-Pol, LiPo, LIP, PLI, orLip) battery. The power module(s) are coupled to and provide power forthe UAV control system 114, the lifting motors 106, and the thrustingmotors 110, the payload engagement mechanism, etc.

In some implementations, one or more of the power modules may beconfigured such that it can be autonomously removed and/or replaced withanother power module while the UAV is landed or in flight. For example,when the UAV 100 lands at a location, the UAV may engage with a chargingmember at the location that will recharge the power module.

As mentioned above, the UAV 100 may also include a payload engagementmechanism (not shown). The payload engagement mechanism may beconfigured to engage and disengage a payload (e.g., an item or acontainer that contains items). In other implementations, the payloadengagement mechanism may operate as the container, in which it containsitem(s). In this example, the payload engagement mechanism is positionedbeneath the frame 104 of the UAV 100. The payload engagement mechanismcommunicates with (via wired or wireless communication) and iscontrolled by the UAV control system 114.

Also coupled to the frame 104 is a pivot assembly 107. In this example,the pivot assembly 107 includes four motors 110-1, 110-2, 110-3, 110-4,referred to herein as thrusting motors, and four correspondingpropellers 112-1, 112-2, 112-3, 112-4, referred to herein as thrustingpropellers. The thrusting motors 110 and the thrusting propellers 112 ofthe pivot assembly 107 may be the same or different than the liftingmotors 106 and lifting propellers 102. In some implementations, thethrusting propellers 112 may have a smaller dimension than the liftingpropellers 102. In other implementations, the thrusting propellers 112may have a larger dimension than the lifting propellers 102. In stillother implementations, one or more of the thrusting propellers may besingle-blade propellers or folding propellers. For example, thethrusting propellers 112-1, 112-2, which may not be used when the pivotassembly 107 is in the thrusting position, may be folding propellersthat fold in the direction of the wind so that they do not generate dragwhen the UAV 100 is moving in a horizontal direction.

The thrusting motors 110 are coupled to a pivot arm 109 that extendsfrom the frame 104 of the UAV 100 and is configured to rotate about anaxis with respect to the frame 104 of the UAV 100. As discussed furtherbelow with respect to FIGS. 6-7, the pivot assembly 107 may includestops that stop the rotation of the pivot assembly at desired positions(lifting position, thrusting position).

In this example, the pivot assembly 107 includes four thrusting motors110 and corresponding thrusting propellers 112 positioned about thepivot arm 109. In other implementations, fewer or additional thrustingmotors and corresponding thrusting propellers may be utilized, providedthere are at least two thrusting motors offset with respect to oneanother about an axis, in this example the pivot arm 109. In the exampleillustrated in FIG. 1, the thrusting motor 110-1 is offset fromthrusting motor 110-3 and thrusting motor 110-4. Likewise, thrustingmotor 110-2 is offset from thrusting motor 110-4 and thrusting motor110-3. Thrusting motor 110-3 is offset from thrusting motor 110-1 andthrusting motor 110-2. Thrusting motor 110-4 is offset from thrustingmotor 110-2 and thrusting motor 110-1.

In this example, as long as the combined force generated by thrustingmotor 110-1 and thrusting motor 110-2 is greater than or equal to thecombined force generated by thrusting motor 110-3 and thrusting motor110-4, the pivot assembly will remain in the lifting position, asillustrated in FIG. 1. For example, the thrusting motors 110-3, 110-4may be disengaged and the thrusting motors 110-1, 110-2 may be engagedand generate a force by rotating the corresponding thrusting propellers112-1, 112-2. If the combined force generated by thrusting motor 110-3and thrusting motor 110-4 is greater than the combined force generatedby thrusting motor 110-1 and thrusting motor 110-2, the pivot assemblywill rotate to the thrusting position, as illustrated in FIG. 2. In someimplementations, the pivot assembly 107 may include a dampener, electricbrake or other inertial component that requires a differential forcebetween the offset thrusting motors to exceed a threshold before thepivot assembly 107 will rotate from the lifting position, illustrated inFIG. 1, to the thrusting position, illustrated in FIG. 2, or from thethrusting position to the lifting position. Likewise, the dampener orother inertial component may be used to position the pivot assembly 107at other angles with respect to the frame 104 of the UAV 100. As usedherein, the term “inertial component” refers to any braking mechanism,whether effective through friction (static, dynamic, or viscous) orinertia used to dampen, restrict, stop, resist, or otherwise biasagainst rotation of pivot assembly 107 about its axis.

FIG. 2 depicts a block diagram of a top-down view of the unmanned aerialvehicle 200 with the pivot assembly 207 in a thrusting position,according to an implementation. Except where otherwise noted, referencenumerals preceded by the number “2” shown in FIG. 2 indicate componentsor features that are similar to components or features having referencenumerals preceded by the number “1” shown in FIG. 1.

When the pivot assembly 207 is in the thrusting position, one or more ofthe thrusting motors 210 may be engaged to provide horizontal thrust viathe corresponding thrusting propeller 212 to propel the UAV 200horizontally. For example, the thrusting motors 210-3, 210-4 may beengaged to generate thrust from the rotation of the correspondingthrusting propellers 212-3, 212-4. Likewise, the thrusting motors 110-1,110-2 (not shown in FIG. 2) may operate at a rotational speed that isless than thrusting motors 210-3, 210-4, or the thrusting motors 110-1,110-2 may be disengaged.

While the implementations of the UAVs discussed herein utilizepropellers to achieve and maintain flight, in other implementations, theUAV may be configured in other manners. For example, the UAV may includefixed wings and/or a combination of both propellers and fixed wings. Forexample, FIG. 3 depicts another block diagram of a top-down view of aUAV 300 that includes a pivot assembly 307 in which the pivot arm 309 isa wing, according to an implementation. Except where otherwise noted,reference numerals preceded by the number “3” shown in FIG. 3 indicatecomponents or features that are similar to components or features havingreference numerals preceded by the number “1” shown in FIG. 1.

Similar to the UAV 100 discussed above with respect to FIG. 1, the UAVincludes a frame 304, motor arms 305-1, 305-2, lifting motors 306-1,306-2, 306-3, 306-4, lifting propellers 302-1, 302-2, 302-3, 302-4,antennas 308, UAV control system 314, power modules, payload engagementmechanism, etc.

Also coupled to the frame 304 is the pivot assembly 307. In thisexample, the pivot assembly 307 includes four thrusting motors 310-1,310-2, 310-3, 310-4 and four corresponding thrusting propellers 312-1,312-2, 312-3, 312-4.

The thrusting motors 310 are coupled to a pivot arm 309 that extendsfrom the frame 304 of the UAV 300 and is configured to rotate about anaxis with respect to the frame 304 of the UAV 300. As discussed furtherbelow with respect to FIGS. 6-7, the pivot assembly 307 may includestops that stop the rotation of the pivot assembly at desired positions(lifting position, thrusting position).

In this example, pivot arm 309 includes a wing shape on either side ofthe frame 304 of the UAV. Thrusting motors and corresponding thrustingpropellers are mounted on the top and bottom sides of each wing shape.In some implementations the pivot arm 309 may be a single arm thatextends through the frame 304 of the UAV 300 such that both wings of thepivot arm rotate together. In other implementations, each wing of thepivot arm may rotate independent of the other wing of the pivot arm. Ifthe wing shapes on either side of the frame 304 rotate independently,each wing will have an offset pair of thrusting motors and correspondingthrusting propellers. If the wings on either side of the frame 304 areaffixed to and essentially part of a single pivot arm that extendsthrough the frame 304, only two offset motors are needed. Thus, whilethe example illustrated in FIG. 3 shows four thrusting motors 310-1,310-2, 310-3, 310-4 and corresponding thrusting propellers 302-1, 302-2,302-3, 302-4, in other implementations there may be additional or fewerthrusting motors and corresponding thrusting propellers, provided thatthere are at least two thrusting motors offset with respect to oneanother about an axis, in this example the pivot arm 309. In the exampleillustrated in FIG. 3, the thrusting motor 310-1 is offset fromthrusting motor 310-3 and thrusting motor 310-4. Likewise, thrustingmotor 310-2 is offset from thrusting motor 310-4 and thrusting motor310-3. Thrusting motor 310-3 is offset from thrusting motor 310-1 andthrusting motor 310-2. Thrusting motor 310-4 is offset from thrustingmotor 310-2 and thrusting motor 310-1.

Similar to the pivot assembly 107 discussed above with respect to FIG.1, as long as the combined force generated by thrusting motor 310-1 andthrusting motor 310-2 is greater than or equal to the combined forcegenerated by thrusting motor 310-3 and thrusting motor 310-4, the pivotassembly will remain in the lifting position, as illustrated in FIG. 3.For example, the thrusting motors 310-3, 310-4 may be disengaged and thethrusting motors 310-1, 310-2 may be engaged and generate a force byrotating the corresponding thrusting propellers 312-1, 312-2. If thecombined force generated by thrusting motor 310-3 and thrusting motor310-4 is greater than the combined force generated by thrusting motor310-1 and thrusting motor 310-2, the pivot assembly will rotate to thethrusting position, as illustrated in FIG. 4. In some implementations,the pivot assembly 307 may include a dampener, electric brake or otherinertial component that requires a differential force between the offsetthrusting motors to exceed a threshold before the pivot assembly 307will rotate from the lifting position, illustrated in FIG. 3, to thethrusting position, illustrated in FIG. 4, or from the thrustingposition to the lifting position. Likewise, the dampener or otherinertial component may be used to position the pivot assembly 307 atother angles with respect to the frame 304 of the UAV 300.

FIG. 4 depicts a block diagram of a top-down view of the unmanned aerialvehicle 400 with the pivot assembly 407 in a thrusting position,according to an implementation. Except where otherwise noted, referencenumerals preceded by the number “4” shown in FIG. 4 indicate componentsor features that are similar to components or features having referencenumerals preceded by the number “3” shown in FIG. 3.

When the pivot assembly 407 is in the thrusting position, one or more ofthe thrusting motors 410 may be engaged to provide horizontal thrust viathe corresponding thrusting propeller 412 to propel the UAV 400horizontally. For example, the thrusting motors 410-3, 410-4 may beengaged to generate thrust from the rotation of the correspondingthrusting propellers 412-3, 412-4. Likewise, the thrusting motors 310-1,310-2 (not shown in FIG. 4) may operate at a rotational speed that isless than thrusting motors 410-3, 410-4, or the thrusting motors 310-1,310-2 may be disengaged.

In this example, because the pivot arm 409 is in the shape of a wing, asthe UAV 400 moves horizontally, the wing shape of the pivot armgenerates a vertical lifting force. The wing shape of the pivot arm 409may be formed of any suitable material such as, but not limited to,carbon fiber, graphite, aluminum, plastic, fiberglass, etc.

The wing shape of the pivot arm 409 is designed to have an airfoil shapeto provide lift to the UAV 400 as the UAV 400 moves horizontally. Insome implementations, utilizing the thrusting motors 410 andcorresponding thrusting propellers 412 in conjunction with the wingshaped pivot arm 409, when the UAV 400 is moving in a direction thatincludes a horizontal component, the rotational speed of the liftingmotors 406-1, 406-2, 406-3, 406-4 and corresponding lifting propellers402-1, 402-2, 402-3, 402-4 may be reduced or eliminated because the wingshape of the pivot arm 409 may provide sufficient lift and keep the UAV400 airborne when thrust in a horizontal direction by the thrustingmotors 410 and thrusting propellers 412 is applied. In implementationswhere the wing shape of the pivot arm 409 includes flaps and/orailerons, the pitch, yaw and roll of the UAV 400 may be controlled usingthe flaps and/or ailerons alone or in combination with the liftingmotors and lifting propellers 402. If the wing shape of the pivot arm409 does not include flaps and/or ailerons, the lifting motors andlifting propellers 402 may be utilized to control the pitch, yaw, androll of the UAV 400 during flight.

FIG. 5 depicts another block diagram of a top-down view of a UAV 500that includes a pivot assembly 507 in which the pivot arm 509 is a wing,according to an implementation. Except where otherwise noted, referencenumerals preceded by the number “5” shown in FIG. 5 indicate componentsor features that are similar to components or features having referencenumerals preceded by the number “3” shown in FIG. 3.

Similar to the UAV 300 discussed above with respect to FIG. 3, the UAVincludes a frame 504, motor arms 505-1, 505-2, lifting motors 506-1,506-2, 506-3, 506-4, lifting propellers 502-1, 502-2, 502-3, 502-4,antennas 508, UAV control system 514, power modules, payload engagementmechanism, etc.

Also coupled to the frame 504 is a pivot assembly 507. In this example,the pivot assembly 507 includes two thrusting motors 510-3, 510-4 andtwo corresponding thrusting propellers 512-3, 512-4. In contrast to thethrusting motors discussed above with respect to FIG. 3, the thrustingmotors 510-3, 510-4 are configured to rotate the thrusting propellers512-3, 512-4 in either direction. For example, when the thrusting motors510-3, 510-4 rotate in a first rotational direction (e.g., clockwise),the thrusting propellers 512-3, 512-4 generate a directional force in afirst direction. When the thrusting motors 510-3, 510-4 rotate in asecond rotational direction (e.g., counter-clockwise), the thrustingpropellers 512-3, 512-4 generate a direction force in a second, oppositedirection.

The thrusting motors 510 are coupled to a pivot arm 509 that extendsfrom the frame 504 of the UAV 500 and is configured to rotate about anaxis with respect to the frame 504 of the UAV 500. As discussed furtherbelow with respect to FIGS. 6-7, the pivot assembly 507 may includestops that stop the rotation of the pivot assembly at desired positions(lifting position, thrusting position).

In this example, pivot arm 509 includes a wing shape on either side ofthe frame 504 of the UAV. In this example, the thrusting motors andcorresponding thrusting propellers are mounted on the top of each wingshape. In other implementations, the thrusting motors and correspondingthrusting propellers may be mounted on the bottom of each wing shape. Inthis implementation, when the thrusting motors 510-3, 510-4 rotate in afirst rotational direction the force generated by the correspondingthrusting propellers 512-3, 512-4 will generate a downward directionforce that will cause the pivot assembly to remain in the liftingposition, as illustrated in FIG. 5. If the thrusting motors 510-3, 510-4are rotated in a second rotational direction, the resulting forcegenerated by the corresponding thrusting propellers 512-3, 512-4 willcause the pivot assembly to rotate to the thrusting position, similar tothe thrusting position illustrated in FIG. 4, above. In someimplementations, the pivot assembly 507 may include a dampener, electricbrake or other inertial component that requires a force generated by thethrusting motors to exceed a threshold before the pivot assembly 507will rotate from the lifting position, illustrated in FIG. 5, to thethrusting position, illustrated in FIG. 4, or from the thrustingposition to the lifting position. Likewise, the dampener or otherinertial component may be used to position the pivot assembly 507 atother angles with respect to the frame 504 of the UAV 500.

FIG. 6 depicts a block diagram of a side-view of a portion of a pivotassembly 607 in a lifting position, according to an implementation. Asillustrated above, the pivot assembly 607 extends from and rotates abouta frame 604 of a UAV. The pivot assembly includes an axis 624 aboutwhich the pivot assembly 607 rotates. The pivot assembly may rotate onbearings, bushings, without the need of any additional motors, gears orother drive mechanisms other than the thrusting motors 610-1, 610-3 andcorresponding thrusting propellers 612-1, 612-3 discussed above. In thisexample, the pivot arm 609 has an airfoil shape of a wing, similar tothe pivot arms discussed above with respect to FIGS. 3-5. Likewise, thethrusting motors 610-1, 610-3 are coupled to motor arms 614-1, 614-3that are coupled to the pivot arm 609 and the thrusting motors 610 arein opposite directions from the pivot arm 609.

The pivot assembly may also include mechanical stops 626-1, 626-1positioned at desired locations that will inhibit rotation of the pivotarm between the lifting position (FIG. 6) and the thrusting position(FIG. 7). For example, a stop bar 628 may extend from the axis of thepivot arm and be configured to engage the mechanical stops 626-1, 626-2to inhibit the rotation of the pivot assembly. For example, as discussedabove and as illustrated in FIGS. 3-4, if the force (F1) generated bythe thrusting motor 610-1 and corresponding thrusting propeller 612-1 isgreater than or approximately equal to the force (F2) generated by thethrusting motor 610-3 and corresponding thrusting propeller 612-3, theresulting differential force will keep the stop bar 628 engaged with themechanical stop 626-1 and the pivot assembly will remain in the liftingposition because the mechanical stop 626-1 is inhibiting rotation of thepivot arm in the first direction. In the lifting position, the thrustingmotors 610 and thrusting propellers 612 may generate force to aid in thevertical lift of the UAV.

However, if the force (F2) generated by the thrusting motor 612-3 andcorresponding thrusting propeller 612-3 exceeds the force (F1) of thethrusting motor 610-1 and corresponding thrusting propeller 612-1, thepivot assembly 607 will rotate about the axis 624 until the stop barengages with the mechanical stop 626-2 and the pivot assembly is in thethrusting position, as illustrated in FIG. 7.

In some implementations, the pivot assembly 607 may include a dampener,electric brake, clutch or other inertial component that requires adifferential force between the thrusting motor 610-1 and the thrustingmotor 610-3 to exceed a threshold before the pivot assembly 607 willrotate from the lifting position (FIG. 6) to the thrusting position(FIG. 7), or from the thrusting position to the lifting position.Likewise, the dampener or other inertial component may be used toposition the pivot assembly 607 at other angles with respect to theframe 604 of the UAV. For example, the dampener, electric brake, clutch,or other inertial component may be selectively engaged to stop and/orprohibit rotation of the pivot assembly 607 at any angle between the twomechanical stops.

FIG. 7 depicts a block diagram of a side-view of a portion of a pivotassembly 707 in a thrusting position, according to an implementation.Except where otherwise noted, reference numerals preceded by the number“8” shown in FIG. 7 indicate components or features that are similar tocomponents or features having reference numerals preceded by the number“6” shown in FIG. 6.

As illustrated in FIG. 7, the pivot assembly 707 has rotated from thelifting position (FIG. 6) to the thrusting position (FIG. 7) because theforce (F2) generated by the thrusting motor 710-3 and correspondingthrusting propeller 712-3 exceeds the force (F1) generated by thethrusting motor 710-1 and corresponding thrusting propeller 712-1. Asshown, the stop bar 728 has rotated about the axis 724 from themechanical stop 726-1 to the mechanical stop 726-2 and will remainengaged with the mechanical stop 726-2 as long as the force (F2) fromthe thrusting motor 710-3 and corresponding thrusting propeller 712-3exceeds the force (F1) generated by the thrusting motor 710-1 andcorresponding thrusting propeller 712-1 because the mechanical stop726-2 is inhibiting rotation of the pivot arm in the second direction.

FIG. 8 is a block diagram illustrating an example UAV control system 814of a UAV. In various examples, the block diagram may be illustrative ofone or more aspects of the UAV control system 814 that may be used toimplement the various systems and methods discussed herein and/or tocontrol operation of a UAV. In the illustrated implementation, the UAVcontrol system 814 includes one or more processors 802, coupled to amemory, e.g., a non-transitory computer readable storage medium 820, viaan input/output (I/O) interface 810. The UAV control system 814 may alsoinclude electronic speed controls 804 (ESCs), power supply modules 806and/or a navigation system 808. The UAV control system 814 furtherincludes a payload engagement controller 812, a network interface 816,and one or more input/output devices 818.

In various implementations, the UAV control system 814 may be auniprocessor system including one processor 802, or a multiprocessorsystem including several processors 802 (e.g., two, four, eight, oranother suitable number). The processor(s) 802 may be any suitableprocessor capable of executing instructions. For example, in variousimplementations, the processor(s) 802 may be general-purpose or embeddedprocessors implementing any of a variety of instruction setarchitectures (ISAs), such as the x86, PowerPC, SPARC, or MIPS ISAs, orany other suitable ISA. In multiprocessor systems, each processor(s) 802may commonly, but not necessarily, implement the same ISA.

The non-transitory computer readable storage medium 820 may beconfigured to store executable instructions, data, flight paths, flightcontrol parameters, pivot assembly, and/or data items accessible by theprocessor(s) 802. In various implementations, the non-transitorycomputer readable storage medium 820 may be implemented using anysuitable memory technology, such as static random access memory (SRAM),synchronous dynamic RAM (SDRAM), nonvolatile/Flash-type memory, or anyother type of memory. In the illustrated implementation, programinstructions and data implementing desired functions, such as thosedescribed herein, are shown stored within the non-transitory computerreadable storage medium 820 as program instructions 822, data storage824 and flight controls 826, respectively. In other implementations,program instructions, data, and/or flight controls may be received,sent, or stored upon different types of computer-accessible media, suchas non-transitory media, or on similar media separate from thenon-transitory computer readable storage medium 820 or the UAV controlsystem 814. Generally speaking, a non-transitory, computer readablestorage medium may include storage media or memory media such asmagnetic or optical media, e.g., disk or CD/DVD-ROM, coupled to the UAVcontrol system 814 via the I/O interface 810. Program instructions anddata stored via a non-transitory computer readable medium may betransmitted by transmission media or signals such as electrical,electromagnetic, or digital signals, which may be conveyed via acommunication medium such as a network and/or a wireless link, such asmay be implemented via the network interface 816.

In one implementation, the I/O interface 810 may be configured tocoordinate I/O traffic between the processor(s) 802, the non-transitorycomputer readable storage medium 820, and any peripheral devices, thenetwork interface or other peripheral interfaces, such as input/outputdevices 818. In some implementations, the I/O interface 810 may performany necessary protocol, timing or other data transformations to convertdata signals from one component (e.g., non-transitory computer readablestorage medium 820) into a format suitable for use by another component(e.g., processor(s) 802). In some implementations, the I/O interface 810may include support for devices attached through various types ofperipheral buses, such as a variant of the Peripheral ComponentInterconnect (PCI) bus standard or the Universal Serial Bus (USB)standard, for example. In some implementations, the function of the I/Ointerface 810 may be split into two or more separate components, such asa north bridge and a south bridge, for example. Also, in someimplementations, some or all of the functionality of the I/O interface810, such as an interface to the non-transitory computer readablestorage medium 820, may be incorporated directly into the processor(s)802.

The ESCs 804 communicate with the navigation system 808 and adjust therotational speed of each lifting motor and/or the thrusting motor tostabilize the UAV, guide the UAV along a determined flight path and/orcause rotation of the pivot assembly from a lifting position to athrusting position or from a thrusting position to a lifting position.

The navigation system 808 may include a global positioning system (GPS),indoor positioning system (IPS), or other similar system and/or sensorsthat can be used to navigate the UAV to and/or from a location. Thepayload engagement controller 812 communicates with the actuator(s) ormotor(s) (e.g., a servo motor) used to engage and/or disengage items.

The network interface 816 may be configured to allow data to beexchanged between the UAV control system 814, other devices attached toa network, such as other computer systems (e.g., remote computingresources), and/or with UAV control systems of other UAVs. For example,the network interface 816 may enable wireless communication between theUAV and a UAV control system that is implemented on one or more remotecomputing resources. For wireless communication, an antenna of an UAV orother communication components may be utilized. As another example, thenetwork interface 816 may enable wireless communication between numerousUAVs. In various implementations, the network interface 816 may supportcommunication via wireless general data networks, such as a Wi-Finetwork. For example, the network interface 816 may supportcommunication via telecommunications networks, such as cellularcommunication networks, satellite networks, and the like.

Input/output devices 818 may, in some implementations, include one ormore displays, imaging devices, thermal sensors, infrared sensors, timeof flight sensors, accelerometers, pressure sensors, weather sensors,etc. Multiple input/output devices 818 may be present and controlled bythe UAV control system 814. One or more of these sensors may be utilizedto assist in landing as well as to avoid obstacles during flight.

As shown in FIG. 8, the memory may include program instructions 822,which may be configured to implement the example routines and/orsub-routines described herein. The data storage 824 may include variousdata stores for maintaining data items that may be provided fordetermining flight paths, landing, identifying locations for disengagingitems, etc. In various implementations, the parameter values and otherdata illustrated herein as being included in one or more data stores maybe combined with other information not described or may be partitioneddifferently into more, fewer, or different data structures. In someimplementations, data stores may be physically located in one memory ormay be distributed among two or more memories.

Those skilled in the art will appreciate that the UAV control system 814is merely illustrative and is not intended to limit the scope of thepresent disclosure. In particular, the computing system and devices mayinclude any combination of hardware or software that can perform theindicated functions. The UAV control system 814 may also be connected toother devices that are not illustrated, or instead may operate as astand-alone system. In addition, the functionality provided by theillustrated components may, in some implementations, be combined infewer components or distributed in additional components. Similarly, insome implementations, the functionality of some of the illustratedcomponents may not be provided and/or other additional functionality maybe available.

Those skilled in the art will also appreciate that, while various itemsare illustrated as being stored in memory or storage while being used,these items or portions of them may be transferred between memory andother storage devices for purposes of memory management and dataintegrity. Alternatively, in other implementations, some or all of thesoftware components may execute in memory on another device andcommunicate with the illustrated UAV control system 814. Some or all ofthe system components or data structures may also be stored (e.g., asinstructions or structured data) on a non-transitory,computer-accessible medium or a portable article to be read by anappropriate drive, various examples of which are described herein. Insome implementations, instructions stored on a computer-accessiblemedium separate from the UAV control system 814 may be transmitted tothe UAV control system 814 via transmission media or signals such aselectrical, electromagnetic, or digital signals, conveyed via acommunication medium such as a wireless link. Various implementationsmay further include receiving, sending or storing instructions and/ordata implemented in accordance with the foregoing description upon acomputer-accessible medium. Accordingly, the techniques described hereinmay be practiced with other UAV control system configurations.

Although the subject matter has been described in language specific tostructural features and/or methodological acts, it is to be understoodthat the subject matter defined in the appended claims is notnecessarily limited to the specific features or acts described. Rather,the specific features and acts are disclosed as exemplary forms ofimplementing the claims.

What is claimed is:
 1. A pivot assembly, comprising: a pivot armconfigured to rotate about an axis; a first motor coupled to the pivotarm and disposed at a first position with respect to the pivot arm; asecond motor coupled to the pivot arm and disposed at a second positionwith respect to the pivot arm, wherein the first motor and the secondmotor are offset with respect to one another; a first mechanical stopthat inhibits a rotation of the pivot arm in a first direction about theaxis; a second mechanical stop that inhibits the rotation of the pivotarm in a second direction about the axis; wherein: the pivot arm isconfigured to freely rotate in the first direction to the firstmechanical stop when a first force generated by the first motor exceedsa second force generated by the second motor; and the pivot arm isconfigured to freely rotate in the second direction to the secondmechanical stop when the second force generated by the second motorexceeds the first force generated by the first motor.
 2. The pivotassembly of claim 1, wherein the first force and the second force are alifting force when rotation of the pivot arm is inhibited by the firstmechanical stop.
 3. The pivot assembly of claim 1, wherein the firstforce and the second force are a thrusting force when rotation of thepivot arm is inhibited by the second mechanical stop.
 4. The pivotassembly of claim 1, wherein: the pivot assembly is coupled to avehicle; the pivot assembly provides a lifting force for the vehiclewhen the pivot arm is inhibited by the first mechanical stop; and thepivot assembly provides a thrusting force for the vehicle when the pivotarm is inhibited by the second mechanical stop.
 5. The pivot assembly ofclaim 4, wherein: the vehicle is at least one of an aerial vehicle, anunmanned aerial vehicle, a ground based vehicle, an unmanned groundbased vehicle, a water based vehicle, an unmanned water based vehicle, aspacecraft, or an unmanned spacecraft.
 6. A pivot assembly, comprising:a pivot arm extending from a frame of a vehicle and configured to rotatewith respect to the frame of the vehicle; a first motor coupled to thepivot arm; a second motor coupled to the pivot arm and offset withrespect to the first motor; and wherein: the pivot assembly isconfigured to rotate to a lifting position when a first force generatedby the first motor is greater than a second force generated by thesecond motor; and the pivot assembly is configured to rotate to athrusting position when the second force generated by the second motoris greater than the first force generated by the first motor; wherein atleast one of the lifting position or the thrusting position is definedby a mechanical stop.
 7. The pivot assembly of claim 6, wherein thefirst force and the second force provide a lifting force for the vehiclewhen the pivot assembly is in the lifting position.
 8. The pivotassembly of claim 6, wherein the first force and the second forceprovide a thrusting force for the vehicle when the pivot assembly is inthe thrusting position.
 9. The pivot assembly of claim 6, wherein thefirst motor and the second motor are approximately perpendicular to theframe of the vehicle when the pivot assembly is in the thrustingposition.
 10. The pivot assembly of claim 6, wherein at least a portionof the pivot arm is formed in a shape of a wing.
 11. The pivot assemblyof claim 6, further comprising: an inertial component that prohibitsrotation of the pivot assembly if a differential force between the firstforce and the second force is less than a threshold.
 12. The pivotassembly of claim 11, wherein the inertial component is at least one ofa brake, a clutch, or a dampener.
 13. The pivot assembly of claim 6,wherein the vehicle is at least one of an aerial vehicle, an unmannedaerial vehicle, a ground based vehicle, an unmanned ground basedvehicle, a water based vehicle, an unmanned water based vehicle, aspacecraft, or an unmanned spacecraft.
 14. The pivot assembly of claim6, wherein when the pivot assembly is in the lifting position, thesecond motor is disengaged and the first motor provides vertical lift tothe vehicle.
 15. The pivot assembly of claim 6, wherein when the pivotassembly is in the thrusting position, the first motor is disengaged andthe second motor provides thrust to the vehicle.
 16. A method ofoperating a pivot assembly, the method comprising: rotating the pivotassembly relative to a frame of a vehicle to a lifting position bygenerating a first force using a first motor that is greater than asecond force generated using a second motor, wherein the pivot assemblyis coupled to the frame of the vehicle and includes a pivot armconfigured to rotate relative to the frame, the first motor coupled tothe pivot arm, and the second motor coupled to the pivot arm and offsetfrom the first motor; providing lift to the vehicle responsive to thepivot assembly rotating to the lifting position; rotating the pivotassembly relative to the frame of the vehicle to a thrusting position bygenerating the second force using the second motor that is greater thanthe first force generated using the first motor; and providing thrust tothe vehicle responsive to the pivot assembly rotating to the thrustingposition; wherein at least one of the lifting position or the thrustingposition is defined by a mechanical stop.
 17. The method of claim 16,wherein the first force and the second force provide a lifting force forthe vehicle when the pivot assembly is in the lifting position.
 18. Themethod of claim 16, wherein the first force and the second force providea thrusting force for the vehicle when the pivot assembly is in thethrusting position.
 19. The method of claim 16, further comprising:disengaging the second motor when the pivot assembly is in the liftingposition; and providing lift to the vehicle by the first force generatedusing the first motor.
 20. The method of claim 16, further comprising:disengaging the first motor when the pivot assembly is in the thrustingposition; and providing thrust to the vehicle by the second forcegenerated using the second motor.